using System;
using System.Collections.Generic;
using System.Linq;
using System.Web;
using Microsoft.Office.Interop.Word;
using System.Data;

namespace WebApplication1
{
    public static class FunctionHelp
    {
        #region Parameters
        private static Microsoft.Office.Interop.Word._Document MyDoc;
        private static Microsoft.Office.Interop.Word._Application MyWord;
        private static object Nothing = System.Reflection.Missing.Value;
        #endregion

        #region Share Methods

        private static Microsoft.Office.Interop.Word._Document OpenWord(Microsoft.Office.Interop.Word._Application wordApp,string templatePath)
        {
            object Visible = false;
            object newTemp = false;
            wordApp = new Microsoft.Office.Interop.Word.Application();
            object templateFile = templatePath + "\\New.doc";
            try
            {
                return wordApp.Documents.Open(ref templateFile, ref Nothing, ref Nothing, ref Nothing, ref Nothing, ref Nothing, ref Nothing, ref Nothing, ref Nothing,
                                            ref Nothing, ref Nothing, ref Visible, ref Nothing, ref Nothing, ref Nothing, ref Nothing);
            }
            catch
            {
                return null;
            }
        }

        private static bool SaveWord(Microsoft.Office.Interop.Word._Document word,string savePath)
        {
            object Visible = false;
            object filename = savePath + "\\King.doc";
            try
            {
                word.SaveAs(filename, ref Nothing, ref Nothing, ref Nothing, ref Nothing, ref Nothing, ref Nothing, ref Nothing,
                                ref Nothing, ref Nothing, ref Nothing, ref Visible, ref Nothing, ref Nothing, ref Nothing, ref Nothing);
                CloseWord(MyDoc,MyWord);
                return true;
            }
            catch (Exception ex)
            {
                CloseWord(MyDoc, MyWord);
                return false;
            }
        }

        private static void CloseWord(Microsoft.Office.Interop.Word._Document word,Microsoft.Office.Interop.Word._Application wordApp)
        {
            object missingValue = Type.Missing;
            object doNotSaveChanges = WdSaveOptions.wdDoNotSaveChanges;
            if (word != null)
                word.Close(ref doNotSaveChanges, ref missingValue, ref missingValue);
            if (wordApp != null)
                wordApp.Quit(ref Nothing, ref Nothing, ref Nothing);
        }

        #endregion

        #region Static Methods
        /// <summary>
        /// 根据Word文档内的BookMark添加数据
        /// </summary>
        /// <param name="dtSource"></param>
        /// <param name="templatePath"></param>
        /// <param name="savePath"></param>
        /// <returns>是否保存成功</returns>
        public static bool ExportWord(DataTable dtSource, string templatePath, string savePath)
        {
            MyDoc = OpenWord(MyWord, templatePath);
            if (MyDoc != null)
            {
                foreach (Microsoft.Office.Interop.Word.Bookmark bm in MyDoc.Bookmarks)
                {
                    bm.Select();
                    switch (bm.Name)
                    {
                        case "书签名":
                            bm.Range.Text = 根据dtSource给书签赋值
                            break;
                        ...
                    }
                }
            }
            return SaveWord(MyDoc, savePath);
        }

        #endregion

        #region Public Methods
        #endregion
    }
}

public static class StringExtension
{
  public staticvoid Foo(this string s)
  {
  　　Console.WriteLine("Foo invoked for {0}",s);
 　}
}